Bravo oil temps and pressure, CHT. info edm 830

[pkofman]

It always amazes me the things that go unnoticed but  because I now have a jpg edm 830 I'm able to see data otherwise not available to me

so yesterday flying in cruise at 10000 ft I took note that my oil pressure was 68 and fluctuating to 67 and 69 . ( in the normal range ) I had 8 on the dipstick, and flying along at 29/2400 .  temps were about 195+/-, outside air temps 9c

I also noticed my cht was about 90 degrees across all cylinders in cruise( hottest one being 405 coolest 350+/- , so I cracked the cowl flaps a bit )

So my question is do the numbers make sense to others, does the engine oil  pressure and temps seem normal and do others see minor fluctuation on the oil pressures. ( these numbers are with the limits of the Poh but just curious what others see)

I am pretty sure that If I did not have this 830 these minor fluctuations would go unnoticed , and I would not be able to fly the machine with this amount of fine tuning.  when the numbers are so fine grained. I gather some would argue more info the better but it might be a bit overkill?

Thoughts on the numbers  and ranges would be helpful 

Pete

[alextstone]

I'm less concerned about the slight oil pressure fluctuations (I see that too) than the temp on the hottest cylinder.

What is the fuel flow?

[pkofman]

39 minutes ago, alextstone said:

I'm less concerned about the slight oil pressure fluctuations (I see that too) than the temp on the hottest cylinder.

What is the fuel flow?

at my power setting I see 17.8 -18.5 gph  +/-   the cht will drop to <400 with a small cowl flap open or reduce power to 28ish mp. my limit has always been 400 max on cht but as I said I'm seeing 405  on cylinder 3 when TIT is about 1635 which is  a lower TIT  than it had been in the past .   My tuning goal has always been  in cruise 29/2400 TIT 1650 cht 400 max and about 17-18 gah cruise at peak tit.... These metrics are my goal, and lately it seemed to have changed.. ( I gather oil pressure looks about correct )

Edited July 24, 2021 by pkofman

[LANCECASPER]

55 minutes ago, pkofman said:

at my power setting I see 17.8 -18.5 gph  +/-   the cht will drop to <400 with a small cowl flap open or reduce power to 28ish mp. my limit has always been 400 max on cht but as I said I'm seeing 405  on cylinder 3 when TIT is about 1635 which is  a lower TIT  than it had been in the past .   My tuning goal has always been  in cruise 29/2400 TIT 1650 cht 400 max and about 17-18 gah cruise at peak tit.... These metrics are my goal, and lately it seemed to have changed.. ( I gather oil pressure looks about correct )

The little bit of money you save on fuel from running at 1650 TIT rather than 1600 TIT will be spent many times over on TIT probes, exhaust components and cylinders. If you can keep the cowl flaps closed at 1600 TIT because of lower cylinder head temps you will gain back efficiency in lower drag.

[alextstone]

I set the FF to 19.7 GPH at those power settings (100 deg ROP).

 

 

[pkofman]

19 minutes ago, alextstone said:

I set the FF to 19.7 GPH at those power settings (100 deg ROP).

 

 

When you mention rich of peak , are you using tit as your metric and what temp is your peak . I have been running 1650 but lately as above 1625 so I’m going to back it down a bit 

[carusoam]

When it comes to fluctuations in oil temp and pressure…

1) The temp is mechanically controlled via the mechanical temperature sensitive valve…

2) So… a digital presentation of what the mechanical device is doing, doesn’t add any extra meaning…

3) the added value of the old mechanical gauges…. They hid the variations by bouncing around in turbulence…

4) oil pressure is going depend on its temperature to some extent…

5) Small variations of a few percent are probably real… just not really important…

6) Some digital displays have a averaging function to display the average value over time…. A few seconds at a time…. This keeps the data from flipping around a lot…

 

7) The Bravo gets an interesting sensor for OilP… because it has a vent to help equalize the change of atmospheric pressure that occurs from 0’msl to the FLs…

There is a whole thread on the funky sensor around here…

8) The key thing is to have oil, so it lubricates things… too hot isn’t good, too cold isn’t any better…

PP thoughts only,

-a-

[Danb]

Lance knows Bravos I’ve learned quite a bit from him and DVA, I have pressure fluctuations also, temps at your altitude I’d be between 355-380 cowls closed. Consider bgees baffling mine lowered temps approximately 10-15*, plus my Old baffling looked good. My last trip five hours, was at 31/2200, 1600, highest CHT 380 averaged 16.5 GPH, much smoother at 2200,  My TAS was 185-188, not much sacrifice for smoothness and fuel consumption, I’m getting prop balanced before annual next week in an effort to smooth more.

[alextstone]

When you mention rich of peak , are you using tit as your metric and what temp is your peak . I have been running 1650 but lately as above 1625 so I’m going to back it down a bit 

I use the peak EGT of leanest cylinder, not TIT

Sent from my Pixel 3 XL using Tapatalk